It is well known that the renin-angiotensin system (RAS) plays a key role in the modulation of many functions in the body. Angiotensin (Ang) II acting on AT1R has a central role in mediating most of the actions of the RAS. However, over the past 10 years, several studies presented evidence for the existence of a new arm of the RAS, the ACE2/Ang-(1-7)/Mas axis. Ang-(1-7) can be produced from Ang I or Ang II via endo or carboxy peptidases, respectively. ACE2 appears to play a central role in Ang-(1-7) formation. As described for Ang II, Ang-(1-7) has also a broad range of effects in different organs and tissues which goes beyond its initially described cardiovascular and renal actions. Those effects are mediated by Mas and can counterregulate most of the deleterious effects of Ang II. The interaction Ang-(1-7)/Mas regulates different signaling pathways such as PI3K/AKT and ERK pathways and involves downstream effectors such as NO, FOXO1 and COX2. Through these mechanisms, Ang-(1-7) is able to improve pathological conditions such as fibrosis and inflammation in organs such as lungs, liver and kidney. In addition, this heptapeptide has positive effects in metabolism, increasing the glucose uptake and lipolysis while decreasing insulin resistance and dyslipidemia. Ang-(1-7) is also able to improve cerebroprotection against ischemic stroke, besides its effects on learning and memory. The reproductive system can also be affected by Ang-(1-7) treatment, with enhanced ovulation, spermatogenesis and sexual steroids synthesis. Finally, Ang-(1-7) is considered a potential anti-cancer treatment since it is able to inhibit cell proliferation and angiogenesis. Thus, the ACE2/Ang-(1-7)/Mas seems to be involved in many physiological and pathophysiological processes in several systems and organs especially by opposing the detrimental effects of inappropriate over-activation of the ACE/Ang II/AT1R axis.
Journal review article
Clinical Science, 2013, Vol 124, Issue 7, p. 443-456